Control device for gun perforators



Oct. 20, 1953 L SPENCER 2,655,993

- CONTROL DEVICE FOR GU PERFORATORS Filed Jan. 22, 1948 Patented Oct.20, 1953 CONTROL DEVICE FOR GUN PERFORATORS Lloyd Spencer, SouthPasadena, Calif., assignor of thirty-three and one-third per cent toThomas C. Bannon, Altadena,

and thirty-three and one-third per cent to John D. Chesnut, NewportBeach, Calif.

Application January 22, 1948, Serial No. 3,673

14 Claims.

My invention relates to gun perforators, more particularly to gunperforators and control devices therefor adapted for cable suspension ina well bore.

Included in the objects of my invention are:

First, to provide a gun perforator which may be suspended from aconventional sand line or from a single strand Wire line such as arecommonly available for other well operations; that is, to provide a gunperforator which obviates the need of a special conductor cable and theattendant surface equipment required by electrically operated gunperforators.

Second, to provide a gun perforator which incorporates a novel controldevice which may be depended upon to re the gun perforator when and atthe level desired, but which is particularly safe to handle at thesurface of the'well, there being series related safety elements whichvirtually eliminate the possibility of accidental operation.

Third, to provide a gun perfo-rator which is divided into readilyassembled sections and which incorporates a novel arrangement whereby adetonating cord or other detonating means may extend continuouslythrough several sections.

Fourth, to pro-vide a gun perforator which provides, without sacricingother valuable features, the features recognized as essential in a gunperforator; namely, substantial barrel length to gun diameter ratio,high number of shots per unit of gun length.

Fifth, to provide a control device for gun pervforators whichincorporates a magnetic drive between a casing engaging wheel and anarming mechanism, the arming mechanism being so arranged that only byreciprocation of the gun perforator within the central portion of apredetermined length of its travel within the well bore can the armingmechanism be manipulated to fire the gun; thus, when the gun perforatoris traveling continuously upward or downward in the well bore thecontrol device is disarmed; furthermore, the control device mayincorporate means whereby the gun perforator cannot fire in any caseunless submerged beyond a predetermined depth in liquid, and stillfurther a time delay may be provided so that, in the unlikely event thatall other safety elements fail, ample warning may be given that the gunis about to fire, such time delay means normally serving to permitmovement of the gun perforator to the exact spot at which perforation isdesired.

With the above and other objects in view as may appear hereinafter,reference is directed to the accompanying drawings, in which:

Figure 1 is a fragmentary partial elevational, partial sectional view ofmy gun perforator.

Figure 2 is an enlarged fragmentary longitudinal sectional view thereof,the upper portion being taken approximately in the plane 2A 2A of Figure3, and the lower portion being taken approximately in the plane 2B 2B ofFigure 3.

Figure 3 is an enlarged transverse sectional view taken through 3 3 ofFigure 2.

Figure 4 is a fragmentary sectional view through 4 4 of Figure 3 showingthe magnetic drive means.

Figure 5 is a transverse sectional view through 5 5 of Figure l showingthe manner in which the gun sections are joined.

Figure 6 is a fragmentary sectional view through 6 6 of Figure 5 showingthe manner in which the detonating cord is threaded between gunsections.

Figure 7 is a fragmentary sectional view taken through 1 1 of Figure 3.

My gun perforator includes a series of gun sections l. Each gun sectionis provided with laterally directed threaded gun barrel bores whichreceive gun barrels 2. The gun bores and barrels are preferably arrangedin three sets displaced l20 from each other. At the inner end of eachgun barrel bore there is formed a cartridge chamber which receives anexplosive cartridge 3. Suitable sealing means 4 covering the bore of thebarrel 2 is clamped between the inner end of the barrel 2 and the socketin which it is screwthreaded. The disk 4 seals off the cartridge 3. Abullet 5 is placed in each gun barrel bore. Each gun perforator isprovided with a longitudinally extending bore for each set of cartridgechambers. Each bore receives a detonator cord 6.

The gun perforator sections are connected by stud bolts 1 set into oneend of each section.

These extend into bores provided in the mating sections, which bores areintersected by lateral slots 8. Nuts 9 are adapted to be inserted inthese slots for threaded engagement with the bolts.

The detonator cord bores of the several gun sections are disposed inaxial alinement. Between the gun sections the detonator cords passthrough pressure sealing washers III. These washers include radial diskportions which are clamped between the gun sections and axial bossportions which extend into Icounterbores in the extremities of `thedetonator cord bores. The boss portions may be press iitted in theircounterbores and in addition tend to expand radially under internalpressure to prevent leakage when the detonator cord is fired. The diskportion has suiiicient radial thickness to withstand the internalpressure without bursting. The disk portion also serves as a seal gasketagainst entrance of liquids in which the gun perforator is immersed.

The uppermost gun perforator section is provided with an axiallydisposed detonator socket I3 of small diameter communicating by suitablepassages I4 with the detonator cord bores. The upper end of theuppermost gun perforator unit is externally threaded for connection to atubular connector member I6. The connector member forms a chamber I1 andits upper end is internally threaded for attachment to a controller bodyI8. The controller body is, in turn, joined to a cable head I8, shownfragmentarily, suspended from a cable, not shown. The cable may be aconventional sand line or a conventional single strand line, known inthe oil industry as a Halliburton line.

The body I8 is provided with a longitudinally extending bore 2I which isoiiset from the axis of the body I8 and receives a firing bar 22. Actionof the firing bar is restrained by devices to be described hereinafter.The lower end of the firing bar, when released, engages a lever 23 setinto a slot 24 provided in the lower extremity of the body I8. The lever23 is provided with a ring pin 25 located in approximately the axialcenter of the body I8.

Mounted within the chamber I1 of the connector member I6 is a time delayunit 26 which incorporates a time delay fuse 21. The time delay unit mayinclude a spool 28 on which is wound the fuse 21, one end of the fusebeing connected to an ignitor 28a set in the upper end of the spool forengagement by the pin 25. The spool 28 may be encased in a shell 29having a depending tubular stem 30 adapted to receive an end of the fuse21. The stem 30 is reduced in part and provided with a seal ring to iitwithin the detonator chamber I3. The fuse 21 actuates a suitabledetonator 3I placed within the detonator chamber I3 and operativelyassociated with the extremities of the detonator cords In the event thatthe seal between the stem 30 and the detonator chamber I3 should fail, ablowout disk 32 is provided in a relief passageway in the gun body Icommunicating with the chamber I1.

The controller body is provided with a vertical and diametricallyextending slot 33 intersected by a transverse bore. The tranSvelS@ DOIGis counterbored at one side of the slot 33 and reduced at the oppositeside of the slot to receive a liner 34 having an enlarged hollow orcupped journal shell 35 tted within the slot 33. An externally threadedcup shaped housing 36 is tted in the counterbore. Its inner end throughan intervening gasket 31 bears against the extended edge of the shell 35to hold the shell in place. A sealing ring 38 may surround the liner 34adjacent the shell 35. The extremity -of the bore containing the liner34 is closed by a cap 39.

The liner 34 is provided with a slot extending therethrough whichreceives a slide bar 4I) flattened on its upper and lower sides. Aportion of the slide bar extends into the chamber formed by the shell 35and housing 36 and the edges of the bar are provided with screw threads.A rotor 4I having an internally threaded bore ts the bar 4I) to move thebar longitudinally in the liner 34 as the rotor is rotated.

The rotor is provided with inserts 42 in the form of permanent magnetsthe extremities of which confront the inner cylindrical surface of theshell 35. A drive wheel 43 having corresponding magnetic inserts 44 isjournalled on the shell 35 within the slot 33. The axis of the shell andliner is displaced from the axis of the controller body I8 to enable oneedge of the drive wheel 43 to protrude for engagement with the interiorof a well casing. Springs 45 set into the opposite side of the body I8bear against the opposite wall of the well casing to maintain the wheel43 in contact.

The body I8 is provided with displaced vertical bores 46 and 41 whichintersect the liner 34 and confront opposite sides of the slide bar 40.The slide bar is p-rovided with a hole 48 which, when the slide bar isreciprocated in the central portionof its travel, may be caused toregister alternately with the bores 46 and v41. The upper bore 46receives a plurality of counter balls 46 backed by a pusher pin 50 and aspring 5I. A reduced end of the pin 50 protrudes from the upper end ofthe body I8. A removable plate 52 holds the spring in place.

The body I8 is provided with a lateral bore communicating between thebore 46 and the bore 2 I in which the ring bar 22 is mounted. Mounted inthis lateral bore is a key ball 53 which ts a channel 54 provided in thering bar and is held therein by the counter balls 48.

Opposite the edge of the slide bar 48, the body I8 and liner 34 formanother lateral bore which receives a key ball 55 adapted to t a channel56 provided in the firing bar below channel 54. The corresponding edgeof the slide bar 4I) is provided in the region of the hole 48 with anotch 51 which permits the key ball 55 to withdraw from the channel 56.

The upper end of the ring bar 22 is provided with a stem 58 whichprotrudes from the upper end of the body I8. A removable ported plate 53slidably receives the stem 58 and overlies the bore 2I. A spring 60surrounds the stem 58 and urges -the firing bar downwardly whenunrestrained by the key balls 53 and 55.

Below the slot 33, the body I8 is provided with a transverse bore 6I ina diametrcal axis passing through the axis of the ring bar bore 2|. Thebore 6I is larger than the bore 2l and receives a plunger 62 having ahole 63 therein through which extends the firing bar 22. The ring bar isreduced to form a shoulder 64 which is adapted -to engage a margin ofthe hole 63 to hold the bar 22 from descending. The plunger 62 is heldin an outward, locking position by a spring 65.

The outer end of the bore 6l is counterbored to receive a cupped piston66 having a sealing ring to isolate the interior of the piston fromexternal fluids. The piston 66 is responsive to external pressuressuiiicient to overcome spring 65 to move the plunger 62 clear of thefiring rod.

Operation of my gun perforator and its control mechanism is as follows:

The gun is loaded and the control device is set as shown in thedrawings; that is, the ring bar is restrained by: (1) key ball 53, (2)key ball 55 and (3) plunger 62. The slide bar 40 is preset in theextreme position to which it tends to move under urge of the magneticdrive coupling between the wheel 43 and the rotor 4l as the gunperforator is moved downwardly within a well casing. A size of thecontroller is, of course, selected which is appropriate for the size ofcasing or liner in which the gun is to be red, even though the casingmay have a larger diameter section above the region to be perforated.

A gear ratio between the drive wheel 43 and the slide bar 40 is selectedsc that a substantial vertical travel of the gun perforator is requiredto move the slide bar its full stroke; for example, the vertical travelmay be as much as thirty feet. When the gun perforator is reciprocatedin the central zone of its travel for a distance of ve to ten feet, thehole 48 is moved back and forth between the bores 4S and 41 causing thecounter balls 49 to move one at a time from bore 46 to bore 41. The bore41 extends to the bottom end of the body I8 and may be closed by a screwplug, not shown, so that after use the counter balls may be retrieved.

When the gun perforator is lowered to the approximate depth at which theperforations are desired the gun perforator is raised suiiiciently toplace the slide bar 40 in its central zone of travel and reciprocated anumber of times corresponding to the number of counter balls 49 abovethe key ball 53. This releases key ball 53. The notch 51 is opposite thekey ball 55 when the slide bar is in its central zone of travel so thatboth key balls are free and permit the firing bar 22 to drive downwardand fire the time delay unit 26. A time delay is pre-selected which issuicient to account for any uncertainty in the interval required torelease the key ball 53 and to permit the gun perforator to be raised orlowered to the exact level at which perforation is desired.

It should be observed that in most cases gun perforating is performedbelow the surface of the liquid within a well bore. However, if theliquid level is below the desired perforation level, water or otherliquid may be added. By reason of the plunger 62 and the submergencepressure responsive piston 66, the gun perforator cannot be operatedunless submerged below a predetermined distance in liquid. Thus, eventhough it should be possible to manipulate the drive wheel when the gunis at the surface of the well until the key balls release the firingrod, the gun will not re. Still further, should, in spite of the safetyfeatures provided, the time delay fuse be set oi, a muied explosion willbe heard to warn that the gun is about to fire.

After the gun has been lowered to the proper depth, and manipulated tore, and then started on its return trip from the well, the slide bar ismoved to an extreme position at which the control mechanism is disarmed,that is, either or both key balls 53 or 55 prevent operation of thefiring bar should it have failed to have previously functioned. As thegun perforator reaches the surface of theliquid the vplunger 62 tends torelock the ring bar.

Having thus described a certain embodiment of my invention,-I do notdesire to be limited thereto, but intend to claim all novelty inherentin the appended claims.

I claim:

l. A gun perforator adapted to be lowered on a cable into a well casingand comprising: a series of gun units; a firing means for said gununits; a primary arming means having an initially unarmed position andcaused to arm by predetermined repeated reciprocation in said casing; asecond arming means associated with said primary arming means and havingunarmed positions at the extreme zones of reciprocation of said primaryarming means and an armed position at the central zone thereof; saidarming means individually restraining said ring means ,when in theirunarmed positions.

2. A gun perforator adapted to be lowered on a cable into a well casingand comprising: a series of gun units; a firing means for said gununits; a primary arming means having an initially unarmed position andcaused to arm by predetermined repeated reciprocation in said casing; asecond arming means associated with said primary arming means and havingunarmed positions at the extreme zones of reciprocation of said primaryarming means and an armed position at the central zone thereof; atertiary arming means responsive to submergence pressure of a liquid insaid casing to move between an unarmed and an armed position; saidarming means individually restraining said ring means when in theirunarmed positions, whereby said ring means is restrained until all saidarming means assume armed positions.

3. A gun perforator adapted to be lowered on a cable into a well casingand comprising: a series of gun units; a ring means for said gun units;a primary arming means having an initially unarmed position and causedto arm by predetermined repeated reciprocation in said casing; a secondarming means associated with said primary arming means and havingunarmed positions at the extreme zones of reciprocation of said primaryarming means and an armed position at the central zone thereof; atertiary arming means responsive to submergence pressure of a liquid insaid casing to move between an unarmed and an armed position; saidarming means individually restraining said firing means when in theirunarmed positions, whereby said firing means is restrained until allsaid arming means assume armed positions; and a time delay meansinterposed between said ring means and said gun units.

4. A gun perforator re control, comprising: a firing member; a keyrestraining said member; a series of retainer elements holding said keyin restraining position; a dispenser for removing said retainer elementsin sequence until said key releases said firing member; and meansincluding a member engageable with a surrounding well casing to actuatesaid dispenser upon reciprocation of said member along said casing.

5. A gun perforator adapted to be suspended from a cable within a wellbore, comprising: a plurality of gun units; an ignitor for said gununits; a firing member for said ignitor; a series of retainer elementsoperable to restrain said ring member; a dispenser for removing saidretainer elements in sequence until said ring member is released; awheel rotatable on the interior of a surrounding casing; and a drivemeans between said wheel and dispenser for actuating said dispenser,said wheel being responsive to predetermined repeated reciprocation ofsaid cable in saidcasing.

6. A gun perforator adapted to be suspended from a cable within a wellbore, comprising: a plurality of gun units; an ignitor for said gununits; a firing member for said ignitor; a series of retainer elementsoperable to restrain said firing member; a dispenser for removing saidretainer elements in sequence until said ring member is released; awheel rotatable on the interior of a surrounding casing; and a magneticdrive between said wheel and dispenser for actuating said dispenser whenwheel is rolled back and forth within said casing a predetermined dis;-tance, said magnetic drive adapted to permit overtravel of said wheel.

7. A control means adapted for cable suspension with a gun perforator,comprising: a firing member adapted to actuate a gun perforator; aretaining means therefor including a series of retainer elements; areciprocable dispenser for removing said retainer elements in sequenceuntil said ring member is released, said dispenser having apredetermined overtravel and arranged to dispense said elements in thecentral zone of its travel; and a drive means for said dispenserincluding a member engageable with a surrounding well casing and adaptedwhen reciprocated therein to effect reciprocation of said dispenser.

8. A control means adapted for cable suspension with a gun perforator,comprising: a ring member adapted to actuate a gun perforator; aretaining means therefor including a series of retainer elements; areciprocable dispenser for removing said retainer elements in sequenceuntil said firing member is released, said dispenser having apredetermined overtravel and arranged to dispense said elements in thecentral zone of its travel; a drive means for said dispenser including amember engageable with a surrounding Well casing and adapted whenreciprocated therein to effect reciprocation of said dispenser; and asecondary retaining means for said firing member adapted to secure saidfiring member when said dispenser is in the end zones of its travel andrelease said firing member when said dispenser is in the central Zone ofits travel.

9. A control means adapted for cable suspension with a gun perforator,comprising: a firing member adapted to actuate a gun perforator; aretaining means therefor including a series of retainer elements; areciprocable dispenser for removing said retainer elements in sequenceuntil said firing member is released, said dispenser having apredetermined overtravel and arranged to dispense said elements in thecentral zone of its travel; a drive means for said dispenser; a wheelrotatable on the interior of a surrounding casing; and a magneticconnection between said drive means and wheel, said wheel adapted uponreciprocation in said casing to reciprocate said dispenser, saidmagnetic connection permitting overtravel of said wheel.

10. A gun perforator, comprising: a pluralitr of gun units adapted to belowered in a well bore; a nring means disposed in proximity to said gununits and including an ignitor, and a firing bar engageable with saidignitor; a latch normally engaging and restraining said firing bar in anunarmed condition; a piston continuously exposed to submergence pressureof a surrounding liquid and operable in response to a predeterminedsubmergence pressure to engage said latch and urge said latch free ofsaid firing bar thereby to arm said firing bar; and means for actuatingsaid firing bar if and when released from said latch.

11. A control means for gun perforators, comprising: a body structurehaving means at its lower end for attachment to a gun perforator andmeans at its upper end for attachment to a suspension cable; a firingmeans for said gun perforator contained in said body structure; anarming device for said firing means having an armed position permittingoperation of said firing means and at least one disarmed positionpreventing operation of said firing means; and means engageable with asurrounding casing and operatively connected with said arming device tocause said arming device to move to and from said armed position onreciprocation cf said body structure in said casing, whereby said armingdevice occupies an unarmed position in the extreme Zones of saidreciprocation and an armed4 position in the central zone thereof.

12. A control means for gun perforators, comprising: a body structurehaving means at its lower end for attachment to a gun perforator andmeans at its upper end for attachment to a suspension cable; a firingmeans for said gun perforator contained in said body structure; anarming device for said firing means having an armed position permittingoperation of said firing means and at least one disarmed positionpreventing operation of said firing means; a drive wheel carried by saidbody structure and engageable with a surrounding casing; and a magneticcoupling operatively connecting said arming device and drive wheel tocause said drive wheel to move said arming device to and from its armedposition upon reciprocation of said body structure in a well casingwhereby said arming device occupies a disarmed position in the extremezones of said reciprocation and an armed position in the central zonethereof.

13. A control means for gun perforators, com,- prising: a body structurehaving means at its lower end for attachment to a gun perforator, andmeans at its upper end for attachment to a suspension cable; a iiringmeans for said gun perforator extending longitudinally in said bodystructure; an arming device for said ring means extending transverselyof said body structure and reciprocable between an armed positionpermitting operation of Isaid firing means and a disarmed positionpreventing operation of said ring means; and means engageable with asurrounding casing and operatively connected with said arming device tocause said arming device to move to and from said armed position onreciprocation of said body structure in said casing, whereby said armingdevice occupies an unarmed position in the extreme zones of saidreciprocation and an armed position in the central zone thereof.

14. A control means for gun perforators, comprising: a body structurehaving means at its lower end for attachment to a gun perforator, andmeans at its upper end for attachment to a suspension cable; a firingmeans for said gun perforator extending longitudinally in said bodystructure; an arming device for said firing means extending transverselyof said body structure and reciprocable between an armed positionpermitting operation of said rng means and a disarmed positionpreventing operation of said firing means; a drive Wheel carried by saidbody structure and engageable with a surrounding casing; and a magneticcoupling operatively connecting said arming device and drive wheel tocause said drive wheel to move said arming device to and from its armedposition upon reciprocation of said body structure in a weil casingwhereby said arming device occupies a disarmed position in the extremezones of said reciprocation and an armed position in the central zonethereof.

LLOYD SPENCER.

References Cited in the le of this patent UNITED STATES PATENTS Number

